Electric switch for mines.



E. LEACH ELECTRIC SWITCH FOR MINES. APPLICATION FILED APR. I2. 1911.

1 ,25'1255. Patented Feb. 19, 1918.

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attozncq EDWARD LEACH, OF IRATHIMEL, PENNSYLVANIA.

ELECTRIC SWITCH FOR MINES.

Specification of Letters Patent.

' Patented Feb. 19, 1918.

Application filed. April 12, 1917. Serial No. 161,454.

To all whom it may concern:

Be it known that I, EDWARD LEACH, a citizen of the United States,residing at Bathmel, in the county of Jefferson, State of Pennsylvania,have invented a new and useful Electric Switch for Mines; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

The present invention relates to an automatic cut-out switch for use inconnection with line and trolley wires, the switch embodying novelfeatures of construction whereby the current will be automaticallycut-off in the event the wire is subjected to an abnormal pull orbreaks,thereby eliminating the possibility of fire or accident due to alive wire.

Further objects of the invention are to provide an automatic cut-outswitch of this character which is compact in its construction, which isthoroughly dependable in its operation, which does not interfere in anymanner with the passage of a trolley wheel along the wire, and which canbe installed without difficulty at any point.

With these and other objects in view, the invention consists in certainnovel combinations and arrangements of the parts as will more fullyappear as the description proceeds, the novel features thereof beingpointed out in the appended claims.

For a full understanding of the invention, reference is to be had to thefollowing description and accompanying drawing, in which Figure 1 is aside elevation of an automatic cut-out switch constructed in accordancewith the invention, parts being broken away and shown in section, andthe switch parts appearing in operative position so that there will bean uninterrupted flow of current through the switch.

Fig. 2 is a similar view, the switch parts being shown as actuated tointerrupt the flow of current.

Fig. 3 is a side elevation of the cut-out switch.

Fig. 1 is a transverse sectional view on the line H of Fig. 1.

Fig. 5 is a View similar to Fig. 1, showing a slight modification, oneend of the switch being broken way.

Fig. 6 is a top plan view of the switch.

Corresponding and like parts are referred to in the followingdescription and indicated 'in all the views of the drawings by a metalend-piece 7 is secured to the opposite end of the switch body 1 andelectrically connected to the feed wire 8 from which current is receivedfrom a suitable source of supply. In the present instance this feed wire8 is shown as connected to a block 9 which is insulated from theendpiece 7 by an interposed member 10, the end-piece 7 and block 9 beingnormally placed in electrical connection by a knife blade switch 11. Anarm 12 projects downwardly from the blade of the switch 11 and carries aplate 13 which is flush with the lower face of the device, andelectrically connects the lower end of the end-piece 7 to the lower endof the block 9. This provides a smooth lower surface for the trolleywheel, and also carries the current from the block 9 to the end-piece 7so that there will be no danger of burning out the switch 11.

A switch terminal block 14 is let into the top of the body 1 so that anotch 14 in one side thereof is exposed within the hollow interior ofthe body, the upper end ofthe terminal block 14 projecting above theswitch body and being connected by a. conducting wire 15 to theend-piece 7. The before mentioned slide 1 is pivotally connected at itsinner extremity to the lower end of an upright switch operating lever16, said lever being pivotally mounted at an intermediate point betweenits ends upon a pivot pin 17 which extends transversely across theinterior of the hollow switch body, and being engaged at its upper endby a compression spring 18. This spring 18 is of just sufficientstrength to resist the normal pull of the wire 6, and in the event of anabnormal pull, such as would be occasioned by a cave-in within amine,the spring 18 would yield and permit the switch operating lever 16to swing upon its pivot 17. A laterally projecting trip finger 19carried by the upper end of the switch operating lever 16 will thenengage an upright trip lever 20 which is also mounted upon the pivotpin17, and swing the trip lever to pull the end of a swinging arm 21 out ofengagement with the notch 1l of the switch terminal block 14. This arm21 is normally horizontally disposed and is pivotally con nected to theend of the trip lever 20, the middle portion of the arm beinglongitudinally slotted at 22 to receive a lateral pin 23 projecting fromthe upper end of a crank 2% which carries a switch plate 25. A spring 26may engage the arm 21 for forcibly swinging the same downwardly as soonas the free end thereof is disengaged from the notch 14 of the switchterminal block 14. The switch plate 25 normally provides a directelectrical connection between the lower faces of the end-pieces 2 and 7,being constructed for cooperation therewith to provide a smooth anduninterrupted track for the trolley wheel. However, as soon as the arm21 is disengaged from the notch 1 1 and swung downwardly by the spring26, as indicated by Fig. 2, the plate 25 is lowered into inoperativeposition, thereby breaking the direct electrical connection between theend-pieces 7 and 2. The electrical connection through the top wire 15,terminal block 1%, arm 21 and other parts of the switch mechanism, isalso broken, so that the wire 6 becomes dead and there is no danger of afire or accident in connection therewith.

The construction shown by Figs. 1 to 41 of the drawing is especiallyadapted for use in mines, since it is designed to cut off the currentautomatically in the event of a cave-in. The normal pull of the wire 6is resisted by the compression spring 18. of the switch actuating lever16, although a cave-in would cause an abnormal pull upon the wire 6 andovercome the resistance of the spring 18, thereby causing the tripmechanism to disengage the swinging arm 21 from the notch 1% of theswitch terminal block 14: and completely cut-off the flow of currentfrom the feed wire 8 to the wire 6. The position assumed by the partswhen the cut-out mechanism has been actuated to interrupt the current isshown by Fig. 2, while the normal position of the parts is shown byFig. 1. One end of the trip pin 19 at the upper end of the switchoperating lever 16 will preferably project through a curved slot 27 inone side of the hollow switch body, the movements of the trip pin withinthe slot 27 enabling an operator to determine when the wire 6 is underproper tension. 7

A slight modification is shown by Fig. 5, in which the switch operatinglever 16 is engaged at its lower end by a tension spring 18 whichoperates to resist the tension in the wire 6. The trip pin 19 at theupper end of the switch operating lever 16 is arranged on the oppositeside of the trip lever 20, and the swinging arm 21 terminates in ahooked end 21 adapted to engage a notch 1 1 in the far side of theswitch terminal block 14. lVit-h this construction the cut-out switchwill be automatically operated in the event theline wire 6 breaks. Thepull of the wire being thus released, the tension spring 18 will swingthe switch operating lever 16 and cause the trip finger 19 to swing thetrip lever 20, thereby disengaging the hooked end 21 of the swinging arm21 from the notched switch terminal block 14. The spring 26 will thentorci bly pull the arm 21 downwardly, thereby breaking the electricalconnection through the terminal block 1 1 and the arm 21, and alsocausing the switch plate 25 at the lower end of the hanger 24c to bemoved downwardly into inoperative position. The general idea ofconstruction is the same as in the previous instance, although the partsare arranged to operate the cut-out when the wire breaks, instead ofwhen there is an abnormal pull thereon.

Having thus described the invention, what 1 claim as new and desire tosecure by Let Patent, is

1. An automatic cut-out switch for line wires, including a switchoperating lever operatively connected to the line wire, resilient meansacting upon the switch operating lever to resist the normal action ofthe line wire thereon, a bodily movable switch plate normallyestablishing direct electrical connection between the source or" currentsupply and the line wire, a swinging trip ar 'i normally holding theswitch plate in operative position, and means actuated by.

the switch operating lever for releasing the trip arm and causing theswitch plate to move into inoperative position.

An automatic cut-out switch for line wires, including a switch operatinglever operatively connected to the line wire, resilient means actingupon the switch operating lever to resist the normal action of the linewire thereon, a trip finger projecting from the said lever, a trip leverarranged in the path of the trip finger, a notched support, an armconnected to the trip lever and normally having the free end thereofengaged by the notched support, and a hanger pendent from the swingingarm and connected to the switch plate to hold the latter in operativeposition, the actuation of the trip means and disengagement of the freeend of the arm from the notched support causing the switch plate to bemoved into inoperative position.

3. An automatic cut-out switch for line wires, including a switchoperating lever operatively connected to the line wire, resilient meansacting upon the switch operating lever to resist the normal pull of theline wire thereon, a notched switch terminal block in electricalconnection with the source of current supply, a trip lever, a swingingarm having one end thereof connected to the trip lever while theopposite end thereof closely engages the notched switch terminal block,current being then conveyed through the terminal block, arm and partsassociated therewith, to the line wire, and means upon the switchoperating lever for swinging the trip lever to disengage the arm fromthe notched switch terminal block when the tension in the line wirebecomes abnormal.

d. An automatic cut-out switch for line wires, including a switchoperating lever operatively connected to the line wire, re silient meansacting upon the switch oper ating lever to resist the pull of the l newire thereon, a notched switch terminal block in electrical connectionwith the source of current supply, a trip lever, a swinging armpivotally mounted upon the trip lever and normally engaging the notch ofthe switch terminal block, means upon the switch operating lever forswinging the trip lever to disengage the swinging arm from the notchedterminal block, a switch plate for normally producing a directelectrical connection between the source of current supply and the linewire, and an operative connection between the switch plate and theswinging arm for moving the switch plate into inoperative position whenthe swinging arm is disengaged from the switch terminal block.

5. An automatic cut-out switch for line wires, including an insulatedswitch body, metal end pieces applied to opposite ends of ti e switchbody, one of the end pieces being in electrical connection with thesource oi current supply, while the opposite end piece is provided witha longitudinal guide, a slide mounted within the longitudinal guide andhaving the line wire connected to the outer end thereof, an uprightswitch operating lever mounted upon the insulated body and connected tothe inner end or" the slide, yielding means acting upon the switchoperating lever to resist the pull of the line wire thereon, a notchedswitch terminal block arranged upon the insulated body and electricallyconnected through the end piece with the source of current supply, atrip lever, swinging trip arm pivoted at one end upon the trip lever andadapted to have the other end. thereof in normal engagement with thenotched switch terminal block, and a trip pin upon the switch operatinglever for engaging the trip lever to swing the same and disengage thearm from the notched terminal block.

An automatic cut-out switch for line ires, including an insulated switchbody, metal end pieces applied to opposite ends thereof, one of the endnieces being provided with a longitudinal guide, while the opposite endpiece is connected to the source oi current supply, a slide mountedwithin the longitudinal. guide and connected at its uter end with theline wire, an upright switch operating lever mounted upon the insulatedbody and pivotally connected to the inner end of the slide, yieldingmeans acting upon the switch operating lever to resist the normal pullof the line wire, a notched switch terminal block mounted upon theinsulated body and connected through the end piece with the source ofcurrent supply, a trip lever, a swinging arm pivotally connected at oneend to the trip lever and adapted to have the other end thereof innormal engagement with the notched switch terminal block, a trip pinupon the switch operating lever for engaging the trip lever to swing thelatter and disengage the arm from the notched switch terminal block, aswitch plate arranged to produce direct electrical connection betweenthe before mentioned metal end pieces, and a hanger pendent from theswinging arm and carrying the switch plate so that the switch plate ismoved into inoperative position when the arm is disengaged from theswitch terminal block.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

EDWARD LEACH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

